The letter on your apparently brass or bronze ring is an Old English Script P, with only ordinary decorations around it, not a school emblem or other "identifiable" decorations. Those facts indicate your ring is a personal last-name Initial ring. The black which surrounds the letter is probably black enamel (or "black finish"), which is very often used on such rings (and brass belt-buckles and buttons) to help the emblem "stand out" more visibly. For an example, see the photo below.